Example 2

Now, let’s say that we want to write a do-file that will accept three
arguments. The first argument is the name of a file to use, the second
argument is the name of a variable in the dataset, and the third argument is
a value of the specified variable indicating the subset of the data that we
want to load into memory.

use `1' if `2'==`3'

We may also want to save the arguments into other macros that have more
meaningful names so that we might use them throughout our do-file.
We can do this with the
args command: